Implement a Queue Using Stack

QueueUsingStack.java

import java.util.*;

class MyQueue {

    private Stack<Integer> s1;
    private Stack<Integer> s2;

    public MyQueue()
    {
        this.s1 = new Stack<Integer>();
        this.s2 = new Stack<Integer>();
    }

    public void queue(int n) {
        System.out.println(" Data Queued " + n);
        this.s1.push(n);
    }

    public void dequeue() {
        if (this.s2.empty()) {
            if(this.s1.empty())
            {
                System.out.println(" No data in Queue");
                return;
            }
            while (!this.s1.empty()) {
                this.s2.push(this.s1.pop());
            }
        }
        System.out.println(" Data Deqeued :" + this.s2.pop());
    }

    public boolean empty() {
        return this.s1.empty() && this.s2.empty();
    }
}


class Test
{
    public static void main(String[] args) 
    {
        MyQueue obj = new MyQueue();
        obj.queue(10);
        obj.queue(20);
        obj.queue(30);
        obj.dequeue();
        obj.queue(40);
        obj.dequeue();
        obj.dequeue();
        obj.dequeue();
        obj.dequeue();

    }    
}